Hydrogels are known for the treatment of cuts, abrasions, bums and similar wounds and consist of a matrix of polymers with a water content of up to 96%. Known hydrogel dressings exhibit less than ideal adherence characteristics and need to be covered with a secondary dressing, and the fluid or bacterial permeability of the gel depends upon the nature of the dressing used. Hydrogels are absorbent and semi-transparent and prior to application they may be refrigerated, such that the cooling effect contributes to the relief of pain.
A hydrogel for use as a wound dressing is described in International Patent Publication No. WO 92/16245, consisting of a water insoluble, water swellable cross-linked cellulose derivative, water and a polyol component. The gel described in this publication is primarily directed to the removal of necrotic tissue, as it reduces the need for the use of a chemical debriding agent or surgical excision. Thus, the known gel provides a dressing which can combine the actions of debriding and cleansing, independent upon the extent of necrosis. Furthermore, the dressing is capable of breaking down necrotic tissue and retaining resultant debris.
However, a problem with known hydrogels, for application as wound dressings, is that their adherency tends to be less than ideal. Furthermore, there is a tendency for these known compounds to disintegrate in the wound and to cause maceration to the skin around the wound.